As one of measures for reducing exhaust gas of a vehicle, there is an output restriction method of restricting torque of an engine with respect to a driver's request torque. According to this method, even though a driver steps an accelerator pedal maximally, a predetermined restriction is given to the torque of the engine, and as a result, it is controlled to produce only an output less than the maximum torque (see, for example, patent literature PTL1).